Unit 16: The laws of Arithmetics

Which number sentence is equivalent to 8 × 12?

• (8 × 10) + (8 × 2)

• (8 × 1) + (8 × 2)

• (8 × 10) + 2

• 8 + (10 × 2)

Which expression is equivalent to 9 × (6 - 1)?

• 54 - 5

• 54 - 1

• 9 × 5

• 9 × 7

What is the correct result of the calculation: 36 × 97 = 36 × (100 - _)?

• 3

• 7

• 4

• 0

Which calculation is wrong?

• 10 + (2 + 8) × 3 = 40

• (10 + 2 + 8) × 3 = 60

• (10 + 2) + 8 × 3 = 58

• 10 + 2 + 8 × 3 = 36

How can Tony write his calculation? Tony wants to add 5 and 6, then multiply by 7.

• 5 + 6 × 7

• (5 + 6) × 7

• 5 × (6 + 7)

• 5 + (6 × 7)

What is the correct order of operations in the expression 3 × 4 + 6?

• First multiply, then add

• First add, then multiply

• Perform multiplication and division last

• Brackets must be used first

Which number sentence uses the distributive rule correctly?

• 3 × (4 + 6) = 3 × 10 = 30

• 3 × 4 + 6 = 3 x 6 + 4 = 18 + 4 = 22

• 3 + (4 + 6) = 10

• 3 × 4 + 6 = 18

Which is the correct expression for calculating 42 × 24?

• 42 × 2 × 12

• 42 × 2 × 24

• 42 ÷ 2 × 12

• 42 × 2 ÷ 24

Eric uses the distributive property for: 5 × (7 + 1). What is the correct calculation?

• 5 × 7 + 5 × 1

• 5 × 8

• 35 + 5

• 35

Ruby is working on a problem with brackets: 3 × 4 × 5. Which rule should she follow to simplify this correctly?

• Use the associative rule

• Use the distributive rule

• Brackets must be applied first

• Use the commutative rule